1. Field of the Invention
The present invention relates to a timepiece such as a portable timepiece including a bezel that can be rotatively operated.
2. Description of the Related Art
A timepiece to which a bezel rotatively operated by a user is mounted to a shell of a case is known in related arts (for example, refer to JP-A-2003-43162 (Patent Literature 1)).
In the timepiece disclosed in Patent Literature 1, the bezel is mounted to the shell so as to be freely rotated by locking a locked flange portion provided continuously around an inner peripheral surface of the bezel to a locking flange portion provided continuously around an outer peripheral surface of a rising portion included in the shell. Here, both the bezel and the shell are made of a metal, and these flange portions are locked by pressing the bezel onto the case with a strong force of a pressing machine and so on to thereby allow the locked flange portion to climb over to a lower part of the locking flange portion. Accordingly, the bezel is prevented from falling off from the case.
Additionally, in the timepiece disclosed in Patent Literature 1, a packing material made of an elastic member is interposed between the outer peripheral surface of the rising portion and the inner peripheral surface of the bezel as well as on the upper side of the locking flange portion. The bezel is held in a still state by the packing material so as not to be flipped. As such packing material is used, the rotation of the bezel is allowed in the case where the user gives a rotation torque exceeding a given degree by the operation of rotating the bezel.
When sand particles enter, or dirt is heaped between the shell and the bezel, the rotation operation of the bezel may be heavy (not smooth). Moreover, deterioration of the packing material proceeds with a lapse of time, the rotation operation of the bezel may be heavy as the deteriorated packing material may stick to the shell and the bezel if the rotation operation is not performed for a long period of time.
In the maintenance for correcting the above situation, after the bezel is removed from the shell once, the shell and the bezel are cleaned, or the packing material is replaced, then, the bezel is mounted to the shell again. To remove the bezel from the shell in the maintenance, a disassembly tool is inserted between the bezel and the shell, and the bezel is pried off by using this tool. The mounting of the cleaned bezel to the shell is performed by pressing the bezel onto the shell with a strong force.
The deformation of the locking flange portion of the shell made of a metal and the locked flange portion of the bezel made of a metal is not easy. Accordingly, as the locking flange portion of the shell and the locked flange portion of the bezel compete with each other with the mounting and removal of the bezel as described above, these flange portions are scraped. Therefore, there is a problem that, as the number of times of removing and mounting the bezel is increased, the engagement allowance between the locking flange portion and the locked flange portion is reduced and the bezel is easily removed from the shell.
There is another problem in the related art timepiece that a dedicated packing material is necessary not only for engaging between the locking flange portion and the locked flange portion for holding the state where the bezel is mounted to the shell but also for preventing the wobble of the bezel and for regulating the rotation operation torque.